Near Field Communications (NFC) include several standards by which two devices in close proximity to one another may exchange information wirelessly. These standards, which include ISO/IEC 18092, specify several aspects of establishing a connection between the devices and how data are to be exchanged. NFC has historically relied on proximity as a security feature, but as malicious parties and eavesdroppers gain greater sophistication in their receiving hardware and in disguising devices to implement man-in-the-middle attacks at the point of data exchange, additional security features are needed to maintain confidence in the privacy of NFC transactions. One such security feature is to encrypt the signals passed between the devices via secret keys; however, encryption adds processing overhead (slowing communications) and is vulnerable to the secret keys being exposed.